docs: def to_sky(self, wcs, mode='all'):
          """
          Convert the aperture to a `SkyEllipticalAnnulus` object defined
          in celestial coordinates.
  
          Parameters
          ----------
          wcs : `~astropy.wcs.WCS`
              The world coordinate system (WCS) transformation to use.
  
          mode : {'all', 'wcs'}, optional
              Whether to do the transformation including distortions
              (``'all'``; default) or only including only the core WCS
              transformation (``'wcs'``).
  
          Returns
          -------
          aperture : `SkyEllipticalAnnulus` object
              A `SkyEllipticalAnnulus` object.
          """
  
          sky_params = self._to_sky_params(wcs, mode=mode)
          return SkyEllipticalAnnulus(**sky_params)